Gmod crashes when joining most RP servers

Often when I go to join a DarkRP server, Gmod crashes with one of those generic ‘the memory could not be “read”’ error messages as soon as it finishes loading. It gets all the way up to the part where I would spawn in the map, and then it just crashes instead. This doesn’t happen with all RP servers, but the vast majority of them, especially I think the more popular ones. I tried moving all my addons to another folder where they wouldn’t be loaded, and the same thing happened. I had also deleted lua-temp, as I’d heard that could help. This is really limiting the number of servers I can play on. By the way, I had even reformatted and reinstalled Windows since I first got that problem (for a different reason, not that) and I’m still getting the problem. It didn’t always happen; a couple years ago I was regularly playing RP just fine on the same computer. Anyone have any idea what the problem is?

I think I’ve found a workaround. If I start a singleplayer game first (I did it in rp_downtown_v2, but it probably doesn’t matter) it doesn’t seem to crash. I may be wrong though, and it is inconvenient, so a solution would still be appreciated.